test(perf): compare saved CLI startup benchmarks (#94812)

Summary:
- Adds saved CLI startup benchmark report comparison flags to `scripts/bench-cli-startup.ts`, plus JSON output coverage and changed-target routing expectations for the new test-helper importer.
- PR surface: Tests +77, Other +109. Total +186 across 4 files.
- Reproducibility: not applicable. as a feature/tooling PR. The prior PR defects were source-proven in review comments and the current head addresses them; I did not run local tests because this review was read-only.

Automerge notes:
- Ran the ClawSweeper repair loop before final review.
- Included post-review commit in the final squash: test(perf): compare saved CLI startup benchmarks

Validation:
- ClawSweeper review passed for head 1afa110f1b.
- Required merge gates passed before the squash merge.

Prepared head SHA: 1afa110f1b
Review: https://github.com/openclaw/openclaw/pull/94812#issuecomment-4748785428

Co-authored-by: clawsweeper <274271284+clawsweeper[bot]@users.noreply.github.com>
Co-authored-by: Felix Isaac Lim <38658663+FelixIsaac@users.noreply.github.com>

src/scripts/test-projects.test.ts

@@ -879,6 +879,7 @@ describe("test-projects args", () => {
           "src/scripts/sync-plugin-versions.test.ts",
           "test/helpers/temp-dir.test.ts",
           "test/scripts/android-pin-version.test.ts",
+          "test/scripts/bench-cli-startup.test.ts",
           "test/scripts/ios-configure-signing.test.ts",
           "test/scripts/ios-pin-version.test.ts",
           "test/scripts/ios-team-id.test.ts",
@@ -886,6 +887,7 @@ describe("test-projects args", () => {
           "test/scripts/kitchen-sink-rpc-walk.test.ts",
           "test/scripts/openai-chat-tools-client.test.ts",
           "test/scripts/report-test-temp-creations.test.ts",
+          "test/scripts/test-projects.test.ts",
           "test/test-env.test.ts",
           "test/vitest-scoped-config.test.ts",
         ],